Lubricating oils



Patented Mar. 22, 1932' UNITED STATES PATENT OFFICE ROBERT C. MORAN, OIWOODBURY, NEW JERSEY, ASSIGNOB TO VACUUM COMPANY, OF NEW YORK, N. Y., ACORPORATION OF NEW YORK nunnzcnrnve one No Drawing.

The present invention relates to improvements in c'ompoundedlubricatingoils.

It is well known that the lubricating qualities of mineral oils may beimproved by the addition of fatty acids, either alone or as constituentsof vegetable or animal fats. The most commonly used fatty acids forimproving the lubricating property of mineral hydrocarbon oils are oleicand stearic acids. The use of these fatty acids involves certaindisadvantages. Oleic acid is liquid at ordinary temperatures and hence"does not adversely aflectthe pour test of lubricating oils when mixedtherewith, but, due to its unsaturated character, oleic acid readilyoxidizes so that mixtures thereof with lubricating oils are decidedlyobjectionable in practice because of their tendency to sludge formationand the development of corrosive acidity. Stearic acid, on the otherhand, is a saturated acid and hence is free from that objection to oleicacid of imparting to its mixtures with lubricating oils the readytendency to sludge formation and the development of particularlycorrosive acidity. But stearic acid is objectionable in its effect onthe pour test of lubricating oils when admixed therewith. For instance,a lubricating oil having a pour test of 5 F. showed, after the additionof 2% stearic acid, a pour test of +36 F.

The present invention resides in the dis covery that the addition, to amineral oil, of the acid product of the interaction of oleic acid andbenzene in the presence of aluminum chloride, will give to the mineraloil a lubricating quality similar to that obtained by the addition ofsaponifiable oils and fats to mineral oils.

The acid may be prepared in the following manner. To 200 gms. of oleicacid dis solved in 400 gms. of dry benzene are added 100 gms. (1.2molecular" proportions) of coarsely powdered aluminum chloride. When thereaction has moderated, the mixture is gently heated (finally to 80 C.)with occasional shaking, .until hydrochloric acid is no longer evolved.The heating requires about six hours. The mixture is then poured into600 c. c. of 20% hydrochloricacid, and

Application filed August 18, 1929. Serial No. 886,489.

the benzene removed by steam distillation. The residual brown, viscousoil may be used as such,.but preferably is fractionated under reducedpressure, the distillate being finally obtained as a yellowish oil,boiling point 5 about 250 C. at 4 m. m., and solidifyng at about 15 C;The crude or redistilled product is particularly suitable for use inimproving the lubricating efiectiveness of lubricating hydrocarbon oils,as it a liquid, w

readily miscible with said lubricating oils and is essentially of asaturated character. Hence, when admixed with lubricating oils, it hasno adverse efiect on the pour test such as is caused by stearic acid,nor does it impart to the mixture the tendency to sludge formation andthe corrosive acidity characteristic of oleic acid.

, As an illustration of this invention, a lubricating oil having aspecific gravity of 0.90

was .mixed with 3% of acid without adverse efiect on the pour test. Themixture, atomized with air at about 300 F. and the atomized streamdirected upon a test piece of Admiralty metal, maintained at about roomtemperature, resulted in no corrosion of the metal after about ten days.Upon similar test conditions, a 3% addition of oleic acid to the samelubricating oil gave a mixture which corroded the Admiralty metal in arelatively the volume of the latter. The addition of these amounts ofthe acid, while greatly improving the lubricating properties of the oil,with corresponding lowering of the interfacial tension against water,has' no effect upon the original pour test of the oil. The

importance of this feature with respect to cold weather lubrication isobvious.

While there has been specified 3% of acid in the above lubricating oilmixture for illustrative purposes, lesser and greater quantities of theacid may be used with advantage in certain cases.

The acid produced by the process herein described is a phenyl-stearicacid of which the precise constitution is not known. As it was firstdescribed by Nicolet and de Milt it may be designated as Nicolet and deMilts acid. Its theoretical formula is believed to be either cfia- (CHh-CH- exam-coon CH4; (CH2) B-cH- (CHQTCOOH :13: or it may contain bothof these isomers. S0

far as known, either or both of these isomers may be used with equalefiectiveness.

What I claim as my invention and desire to secure by Letters Patent is:

A lubricant consisting chiefly of mineral lubricating oil, with theaddition of a relatively small amount of Nicolet and de Milts acid.

ROBERT C. MORAN.

